9421888 Laughlin A theoretical study will be made of the microscopic quantum mechanics of high temperature superconductors using a strategy that emphasizes experimental phenomenology over first principles computation. The goals of the work are to reconcile the enormous number of experimental facts in this field with one another, to prioritize these facts, to distinguish genuinely new physical behavior from that due to sample imperfection, and to motivate significant new experiments. This approach reflects the view that the important new physical ideas in this field have already been articulated, and that the task is now to distinguish among them in the laboratory. Theory must be involved in this process because the evidence of new physics is subtle and is often found in the inconsistencies between one experiment and another. Also, it has now become evident that experimental confusion tends not to clear up by itself in this field. Some specific computations for magnetic Hamiltonians are also proposed as is some further investigation into the properties of superconducting states that violate time-reversal symmmetry. This is a natural extension of work on anyon superconductivity performed on the previous grant. %%% A program of theoretical research on high temperature superconductivity will be undertaken which emphasizes interpreting existing experimental results and building on these to create new models and suggesting new experiments. ***
